Configuring the Standby Server

The third step requires the you to enter an alias public IP address.
Proceed by clicking on step 3. HA-OSCAR will pop up the Standby server initial
network Configuration screen shown in Figure 5. Users normally use this public
IP address as a virtual entry point to access the head node. When the failover
occurs, the standby server will take over this address so users can continue
accessing the cluster as if nothing has happened. The normal procedures within
this step are:

Enter the alias public IP for the eth1 interface. When the failover occurs,
the standby server will automatically clone the cluster public IP on the
designated network interface, probably eth1.

Determine whether the standby local IP address HA-OSCAR has selected is
occupied. If this IP address is in use, please select a new one. Otherwise,
keep this default.

Leave the last two items unchanged.

Click Add Standby Server.

Figure 5. Standby server initial network configuration

This step will take less than a minute. When the successful status window
pops up, click on the Close button.

Retrieve Standby Server MAC Address (For PXE Boot) and Build the Image on
its Local Drive

Pay close attention to the following procedures to retrieve the standby
server's MAC address for PXE booting before building its images on the local
drive. One of the standby server network interfaces, typically eth0, connects
to the private LAN and broadcasts its MAC address during its network boot.

Whenever the primary server is ready to build the standby server image, it
starts cloning its images with the collected addresses. Consequently, the
standby server will fetch the image by network booting the standby server via
PXE (or floppy) from the primary server or an optional image server on its
local file system. When the cloning succeeds, the server will reboot from its
hard disk. This marks the completion of the standby server installation.

To assign the standby server's MAC address and build a local image on the
standby server, proceed to step 4 in "Network Setup & Make boot server."
HA-OSCAR will display the standby server MAC address configuration screen as
shown in Figure 6.

Figure 6. Standby server MAC address configuration

Step 4 contains the following procedures:

Click on the Setup Network Boot button.

Click on the Start Collect MAC address button to instruct the primary
server to collect the standby server's MAC address.

Switch to the standby server terminal, configure its boot sequence to start
with the network boot, and reboot the standby system. Make sure the standby
server eth0 is connected to the local switch where the primary server PXE
daemon will listen to the broadcast boot request. Otherwise, the primary
server will not be able to collect the standby MAC address in the next
step.

Toggle back to the primary server screen; it should now show the standby
server's MAC address (Figure 7).

Completing the HA-OSCAR Installation

Having completed all four steps, the cluster should have all of its packages
installed. The cluster should be ready to use or test. HA-OSCAR also provides
a web-based management to customize the HA-OSCAR configuration, including the
capability to enable new outage monitor/detection modules and failover
capabilities. However, this is a feature for advanced users only, as it may
cause invalid cluster configurations if you incorrectly configure HA-OSCAR
parameters. The next section elaborates on this topic.

HA-OSCAR Monitoring and Configuration Webmin (Optional)

HA-OSCAR provides a default self-healing system resource and outage
monitoring health and recovery mechanism. It also provides a web-based service
monitoring and configuration program based on WebMin and Mon. You can use HA-OSCAR
Webmin to customize resource managing, configuring, and service monitoring.

The following sections describe step by step how to manually configure
the virtual network interface, (heartbeat) detection channel, and optional service
monitoring configurations. Again, we intended to support the following
procedures and features only for advanced users. The normal initial head node
configuration steps are:

Set up detection channels and configurations on the primary server.

Set up detection channels and configurations on the standby server.

Enable the optional HA-OSCAR service monitoring (only for advanced
users).

Primary Server Setup

Access HA-OSCAR Webmin by opening http://localhost:10000 (but only if you
have it running) and selecting the HA-OSCAR category to configure the system
(Figure 8). A manual configuration (Figure 9) involves the following
steps:

Add a virtual network interface to eth0 and eth1.

Define channel detection: a public network and its virtual interface
(virtual public IP, which is the same public IP for both primary and standby
severs) and a private network and its virtual interface. This is for IP
cloning and channel detection.

Other users also can later log in and manage your system with the web-based
tool.

Figure 8. Step-by-step instructions to set up a
virtual network interface and detection channel